Guiding means for zig-zag sewing machine



O 2 96 w. ENGEL 3,005,427

GUIDING MEANS FOR ZIG-ZAG SEWING MACHINE Filed Feb. 29, 1956 4 Sheets-Sheet 1 fm emorz' Way-1,14 A/g avg Oct. 24, 1961 w. ENGEL 3,005,427

GUIDING MEANS FOR ZIG-ZAG SEWING MACHINE Filed Feb. 29, 1956 4 Sheets-Sheet 2 Oct. 24, 1961 w. ENGEL 3,005,427

GUIDING MEANS FOR ZIG-ZAG SEWING MACHINE Filed Feb. 29, 1956 4 Sheets-Sheet 5 I'm/anion mum/v4 01 451.

AGAF VT Oct. 24, 1961 w. ENGEL eumm: MEANS FOR ZIG-ZAG SEWING MACHINE 4 Sheets-Sheet 4 Filed Feb. 29, 1956 v s i The invention relates to a sewing machine of the type for zig-zag stitching, and particularly to such a machine for household use.

It is an object of the invention to arrange a machine of this type in a manner that even the housewife is enabled to produce the most variegated sewing pictures with greatly different numbers of stitches.

Heretofore sewing machines of the zigzag type were known in which a control shaft is provided which is driven in the customary manner by the arm shaft of the machine. Control cams were mounted upon this control shaft which, by way of a follower mechanism, must influence the movement of the producing means of the sewed picture. The control cam mechanism for this purpose was constituted by control disks which were mounted on the control shaft in the manner of a nest or a stack. The follower mechanism was arranged in such a manner that out of the stack one cam disk at a time was followed, so that the Zig-zag mechanism of the machine was operated by way of suitable setting devices.

It is a primary object of the invention to arrange the control cam mechanism in the form of an endless band or belt provided along its outer surface with control cams or the like. Such a belt can be so constructed as to have a much greater peripheral length than it has been possible heretofore to obtain with conventional cam disks. Consequently, there is a possibility with the control band or belt in accordance with the invention to produce a greater variety of the different sewed patterns with different numbers of stitches than it was possible to obtain heretofore.

The outer broad side of the control or guide belt can be utilized not only with a single row of cam formations or the like, but also with several rows of cams or the like disposed parallel to each other. Also the short sides of the guide belt can be provided with control cams or the like. This obtains that within a small space a control mechanism for followers can be formed which permits of producing even complicated sewing patterns.

Control or guide belts of different lengths can be combined interchangeably in the arrangement in accordance with the invention. The difference in length is compensated for by the spring-biased pivot mounting of the ten sioning idler.

It is recommended for the purpose of achieving even or balanced advancing ofthe guide, belt by the control shaft to provide the guide belt with teeth on its inside which engage the teeth of the drive pinion on the control shaft and also on the tensioning idler.

The outer cam formations and the inner teeth of the guide belt can be produced from flexible plastic material which provides an economical guide mechanism. The seamstress thus may have available a number of different interchangeable guide belts for the sewing operations.

The guide belt may also be formed of separate joint links in the manner of a guiding chain. In this connection the inwardly directed eyelets of the joint can be formed to constitute the teeth which cooperate with the.

driving pinion. This makes it possible to compose a guide chain of different joint links for the purpose of 3,005,427 Patented Oct. 24, 1961 producing the most varied sewing patterns. Thus, it is possible by means of few differently formed links, for example five links, to produce a large number of sewing patterns which is satisfactory for practical purposes.

Especially where a plurality of followers are used, it is essential to keep the guide belt accurately positioned so that each follower reliably engages its respective control cam row. For this purpose the guide belt can be fitted with border disks on both sides, at the pinion as well as at the tensioning idler.

Finally, it is also possible in the arrangement in accordance with the invention upon removing the guide belt and the pinion to provide the control shaft with one or more interchangeable guiding cams. In this connection these guiding cams can act upon the same cam follower mechanism as the guide belt. This objective is attained in that the follower mechanism is suitably constructed so that the contact end of the follower finger engages the guiding belt radially with reference to the gears which engage the belt.

In the drawings which illustrate embodiments of the subject of the invention FIG. 1 is a plan view of the open arm of the sewing machine illustrating the arrangement of the control belt,

FIG. 1a is a perspective view of a sewing machine showing cutouts at the upper portion of the arm and at the head to illustrate the power transmission from the guide belt by way of the needle bar oscillator;

FIG. 2 is a sectional view along the line IIII in FIG. 1;

FIG. 2a is a view similar to FIG. 2 which is illustrative of a diiferent type of cam arrangement on the belt;

FIG. 2b is a plan view of the embodiment shown in FIG. 2a;

FIG. 3 is a plan view of'the open machine arm in accordance with FIG. 1, where the guide shaft is provided with a cam disk;

FIG. 4 is a section along line IVIV of FIG. 3;

FIG. 5 is a front view of the control disk with the chain links in place;

FIG. 6 is a schematic illustration of the different chain ks;

FIG. 7 is. an elevational view of the chain links arranged in the single tier;

FIG. 8 is an elevational view of the chain links arranged in a double tier.

The main. shaft 1 is journalled in the arm 2 of the sewing machine. and supports a worm 3 which drives the control shaft 5, also journalled in the arm, by way of the worm gear 4. The driving pinion 6 is fastened to the control shaft 5 and presents teeth 6a in engagement with control belt, 7. The guide belt 7 which is preferably of plastic material is provided on the inside with teeth 7a which cooperate with teeth 6a of the pinion 6 and on the spring biased idler roller 8.

The guide belt is provided on its outer side with control cams 9; which by way of the feeler or follower 11 which. is pivoted at 10 and draw bar 12, oscillates the needle; bar oscillator 15 which carries the needle bar and isrnounted to swing about the vertical axis 13, thereby producing sewing patterns which correpsond to the shape of'the cam 9. A pressure spring 15a completes the pressure connection between the follower lever 11 and the guide belt 7.

In FIG; la the upper structure of the sewing machine is shown with the material carrying plate 101, the standard 102 to which is connected the arm 2 which at its free end. defines the head 103 of the sewing machine. The balance wheel 104 is disposed on the outside of the standard 102 where it is mounted in the usual manner upon 3 the arm or drive shaft 1. The arm 2 is closed at the top by means of a removable lid 105. In the head 103 the axle 13 provides a pinpoint bearing for the oscillator 15 in which the needle bar 14 can reciprocate vertically. At the lower end of the needle bar the needle 106 is located which can enter the stitch plate 107. The shaft 10 on which the follower arm 11 is pivotally mounted is seated in a bearing 199 provided in the housing wall 108 While the arm shaft 1 is journalled in an aperture 110 provided in the front Walls of the arm 2.

The pivot arm 16 for the biased idler roller (FIG. 1) is journalled in the bore 17 of the arm 2 by means of the bolt 16a to which it is secured. The idler roller 8 is rotatably mounted on the bolt 18 which is also secured to the pivot arm 16. Spring 19 which is secured at one end to the arm 2 by means of pin 20 and at the other end to the pivot arm 16 provided for tightening the guide belt '7 the length of which may vary. To guard against axial displacement of the guide belt 7 on the drive pinion 6 and the idler roller 8 the axial distance between which depends on the tooth length of the guide belt 7, the two wheels are provided with border disks 21, 21a, 21b, 210.

The guide belt 7 can be interchanged in a simple manner with a guide cam disk 22 in that the cam disk 22 is mounted upon the control shaft 5 in lieu of the drive pinion 6. The follower arm 11 is arranged in such a manner that in both cases its feeler tip 11a cooperates with the control cams without readjustment of its position.

The guide belt '7 may also be constructed in the form of a chain having releasable chain links. In that event the links 23 are provided on their inner side, i.e. on the side which faces the drive pinion 22, with lugs 24 in the bores 25 of which pins 26 are located to connect the links.

Covering disks 27 are provided to prevent movement in axial direction of the pins 26. The lugs 24 serve at the same time as teeth of the chain and they engage the tooth gaps 28 of the chain drive gear 22'.

The chain 23 may be constituted by a single row of links as in FIG. 7 or of a plurality of link rows as in 'FIG. 8. Each of the rows of links is associated with a spring biased feeler or follower lever 11 having a feeler tip 11a. In this manner it is possible, for example, to control the needle deflections with one row of the links, and the material feeding dog or the stitch length and stitch direction with the other row of links.

Since it is possible in accordance with the invention to operate optionally either with the guide belt or with cam disks, the position of the pivot point of the follower arm 11 is chosen in a manner that the follower tip 110 moves substantially radially with respect to control shaft center as the lever 11 swings outwardly.

For the same reason the guide surfaces of the chain links are developed as departing from an are having the control shaft as its center. The height of the links determines the magnitude of the deflection of the needle or of the stitch. The greatest deflection to the left is obtained with the link 23 and the greatest deflection to the right with link 23".

It is evident that only a few links having different cam surfaces will suffice to compose the most varied sewing patterns. Thus, for example, individual monograms can be made in a short period of time without the need of special curves.

For the purpose of obtaining still greater use from the guiding belt the edges thereof can also be provided with cams 9a. In FIG. 2a the guide belt 7 is provided at the top and at the bottom edges with cam surfaces 9a at spaced intervals. In this case the follower arm 11 and its connection with the oscillator 15 must be shaped in such a manner that the follower arm tip 110 can engage the control cams 9a at the edges of the belt 7 and that the movement of the follower arm is properly effective on the oscillator 15, or on the toothed feed dog and the like in a manner customary with automatic machines of this type. For example, if the cam surface 9a at the top of the belt is used for controlling the operation of a feed dog, a follower 11a as shown in FIG. 2 may be employed.

The follower arrangement may also be similar to that indicated at 60 in FIG. 1 of my copending earlier application Ser. No. 560,011.

As shown in FIG. 2a the follower is mounted to rock about a horizontally extending pivot pin 10a. and is linked to the needle bar oscillator by means of a bar 12a.

Having now described my invention with reference to the embodiments thereof illustrated in the drawings, I do not wish to be limited thereto, but what I desire to protect by Letters Patent of the United States is set forth in the appended claims.

1. A zig-zag sewing machine of the type having a guiding means presenting cam surfaces operative to guide the movements of the needle bar, and including a control shaft disposed vertically in the arm of the machine adapted to drive said guiding means and operatively connected to the drive shaft of the machine, a drive gear disposed horizontally in the arm of the machine on said control shaft and having recesses, a cam follower mechanism in engagement with said cam surfaces, a needle bar oscillator and a needle bar mounted to respond to the movements of said cam follower, a flexible belt constituting said guiding cam means and having inwardly projecting conformations defining teeth engaging said recesses, said belt presenting guiding cam surfaces of varying elevation determining the direction and magnitude of the lateral needle deflections, and a spring biased idler roller spaced from and disposed in parallel alignment with said drive gear and having recesses engaged by said teeth, said belt being of the endless belt type and being disposed around said drive gear and said idler roller, said cam surfaces being defined in sections of said belt, said teeth being disposed endwise of said sections, and said belt being additionally provided with cam surfaces at least along one edge thereof.

2. A zig-zag sewing machine of the type having a guiding means presenting cam surfaces operative to guide the movements of the needle bar, and including a control shaft disposed vertically in the arm of the machine adapted to drive said guiding means and operatively connected to the drive shaft of the machine, a drive gear disposed horizontally in the arm of the machine on said control shaft and having recesses, a cam follower mechanism in engagement with said cam surfaces, a needle bar oscillator and a needle bar mounted to respond to the movements of said cam follower, a flexible belt constituting said guiding cam means and having inwardly projecting conformations deflning teeth engaging said recesses, said belt presenting guiding carn surfaces of varying elevation determining the direction and magnitude of the lateral needle deflections, and a spring biased idler roller spaced from and disposed in parallel alignment with said drive gear and having recesses engaged by said teeth, said belt being of the endless belt type and being disposed around said drive gear and said idler roller, said cam surfaces being defined in sections of said belt, said teeth being disposed endwise of said sections, and said sections being formed of plastic material.

3. A zig-zag sewing machine of the type having a guiding means presenting cam surfaces operative to guide the movements of the needle bar, and including a control shaft disposed vertically in the arm of the machine adapted to drive said guiding means and operatively connected to the drive shaft of the machine, a drive gear disposed horizontally in the arm of the machine on said control shaft and having recesses, a cam follower mechanism in engagement with said cam surfaces, a needle bar oscillator and a needle bar mounted to respond to the movements of said cam follower, a flexible belt constituting said guidg 9 .1. 1 D WQS and having inwardly projecting conformations defining teeth engaging said recesses, said belt presenting guiding cam surfaces of varying elevation determining the direction and magnitude of the lateral needle deflections, and a spring biased idler roller spaced from and disposed in parallel alignment with said drive gear and having recesses engaged by said teeth, said belt being of the endless belt type and being disposed around said drive gear and said idler roller, said cam surfaces being defined in sections of said belt, said teeth being disposed endwise of said sections, and border disks disposed adjacent the edges of said belt on said drive gear and on said idler roller.

References Cited in the file of this patent UNITED STATES PATENTS Ostrom Aug. 12, 1-884 Mace July 24, 1923 Brase Feb. 16, 1926 Brase Feb. 16, 1926 Rader Dec. 21, 1926 Mahany June 3, 1941 Burrus et a1 Oct. 19, 1948 Garner et a1 Apr. 10, 1956 Waterman Nov. 1, 1960 

